Brrring it on, winter

Arctic jet stream bringing wave of brutal lows

January 15, 2009|By James Janega, TRIBUNE REPORTER

Falling temperatures on Thursday may add the coldest day since 1996 to what is already the Chicago area's coldest winter in eight years, sending city officials to emergency staffing levels and closing schools from Kenosha to Kankakee.

The mercury will tumble Thursday as winds kick up, mixing 20 m.p.h. gusts by nightfall with lows in downtown Chicago from 10 below zero Fahrenheit to 20 below in outlying areas. Concerned Chicago leaders sent Police and Fire Department brass to the city's cold weather command center, ordered well-being checks for the elderly and disabled and threw open warming centers to all who needed them.

Thursday's bitter cold is a fluke of a jet stream, a twist in the howling atmospheric winds around the North Pole. They buckled overnight, slashed across the Canadian prairie and aimed straight at Chicago, drawing in their wake subzero temperatures and cruel, crystalline skies.

"Nothing good," National Weather Service meteorologist Gino Izzi said. "It's coming almost literally from the North Pole."

The brutal arctic temperatures will linger until Friday. A return to the teens and comparative warmth will come by Saturday morning, Izzi said.